In recent years, methods for improving the display luminance of a color display device have been proposed. As an example, there is a liquid crystal display device with a unit pixel in which red (R) color pixel, green (G) color pixel, blue (B) color pixel, and white (W) color pixel are arranged in a predetermined order along a row direction.
Each of the color pixels of the unit pixel has a unique transmittance characteristic with respect to an applied voltage, which is referred to the V-T characteristic. Thus, there may be a case where peak transmittance is obtained at different voltages in these color pixels. In particular, the V-T characteristic of the blue color pixel differs greatly from those of red and green color pixels. The peak transmittance of a blue color pixel is obtained at a relatively low voltage while the peak transmittance of each of a red color pixel and a green color pixel is obtained at a relatively high voltage. Thus, a voltage value is set for each color pixel based on its peak transmittance in order to maintain a white balance.